issues relaying to 365 for one user

[admiral_sulu]

hybrid setup, exchange 2013, and 365.

all users are on 365, copiers and couple of servers send email to 365 via exchange relay.

having an issue with single new user.  report emailed from server, goes to exchange 2013 relay connector, then to 365.

emailed report has 3 people copied on it, the two preexisting users received the email, the new user did not.

I ran PS commands on my exchange server for message trace, and it shows the email being sent out to all 3 users.

nothing appears in quarantine on 365.

message trace on 365 from the report email to the new user returns nothing though,  

what am I missing?  its almost like 365 is saying "nope" for these emails to this one person, but no recording the nope anywhere.

is there another place to look?

[#2]

@admiral_sulu : You might have already checked this but just to confirm, this new user was provisioned on-premises and then migrated to office 365? or a remote mailbox was created directly in office 365. Check if remote routing address is properly stamped against the user. Another good test would be if you have any mailbox on-premises or you can create one, see if you are even able to send emails to the new user from your exchange server.

[#3]

by remote routing address, do you mean the onmicrosoft.com email account?
that seems correct
I have created mailboxes since then and no problems have been reported.
create the mailbox on exchange, then migrate to 365.

[#4]

@admiral_sulu : Yup, the remote routing address is of the format: user@mail.onmicrosoft.com, you should see that in your email address policy/ proxy addresses of users you migrated.

Going forth, you can either create the mailbox on exchange and migrate it or simply use the following command to create the mailbox directly in cloud :

Enable-RemoteMailbox "Kim Akers" -RemoteRoutingAddress "kima@contoso.mail.onmicrosoft.com"

This has same effect as migrated user.

Ref: https://docs.microsoft.com/en-us/powershell/module/exchange/enable-remotemailbox?view=exchange-ps

Just to confirm, the issue has been resolved and you dont need any further assistance on this one?